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Fri June 28, 2013
'Brainwashed' Examines the Value of Brain Scans
Originally published on Mon July 1, 2013 9:13 am
IRA FLATOW, HOST:
This is SCIENCE FRIDAY. I'm Ira Flatow. Seems like every other week, a new study, complete with a colorful brain scan and a great headline, links a spot on the brain with the way we act. This is your brain on love; this is your brain on prayer; this is your brain on politics. But can a scan of your brain really tell you something about your beliefs and behaviors?
Does this steady stream of neuroimaging studies add to our knowledge of the brain, or do the scan studies run the risk of overly simplifying human behavior, boiling it down to all nature, no nurture? A new book takes a closer look at neuroimaging and what we can and can't learn from it. It's called "Brainwashed: The Seductive Appeal of Mindless Neuroscience." And joining me to talk more about is one of our co-authors.
And if you'd like to talk about it, our number is 1-800-989-8255. You can also tweet us @scifri. We have a whole panel here to discuss it. Let me introduce the co-author first. It's Sally Satel is a practicing psychiatrist and co-author, with Scott Lilienfeld of "Brainwashed: The Seductive Appeal of Mindless Neuroscience." She is a resident scholar at the American Enterprise Institute, and she joins us from NPR in Washington. Welcome to SCIENCE FRIDAY.
SALLY SATEL: Thanks so much, Ira.
FLATOW: You're welcome. Give us an idea of what you mean by mindless neuroscience.
SATEL: Yes, the mindless part is very important because it's the mindless neuroscience that we critique in our book, not neuroscience. In fact both Scott and I regard neuroscience, neuroscientific discoveries, as perhaps among the greatest intellectual achievements of recent history. And the technology is remarkable, with brain imaging being probably the signature tool of modern neuroscience.
So on that - with that as a backdrop, what interested us was the migration of this tool, and of brain-based data in general but mainly brain imaging, the migration of neuroscience out of the lab, and the clinic to a lesser extent, and into the public domain, in other words into courtrooms where it might be invoked to say something about a criminal's mental state, could he form intent to commit a crime, is he rational, can he control himself; in the marketing sphere; and in the area of addiction, which happens to be my clinical expertise; and also in terms of how we understand biological explanations of behavior in the context of thinking about human responsibility.
FLATOW: As you can imagine, it's pushed - there's been a lot of pushback from your book, from people who are in the field, and I have some of them with me here. I want to introduce them. Gary Marcus is a professor of psychology and director of the NYU Center for Language and Music, and he's here in our New York studio. Welcome back to SCIENCE FRIDAY.
GARY MARCUS: Thanks very much for having me back.
FLATOW: Russell A. Poldrack is the director of the Imaging Research Center and a professor of psychology and neurobiology, University of Texas at Austin. He joins us from KUT in Austin. Welcome to SCIENCE FRIDAY.
DR. RUSSELL POLDRACK: Hi Ira, thanks for inviting me.
FLATOW: You're welcome. David Eagleman is the director of the Initiative on Neuroscience and Law and a neuroscientist at Baylor College of Medicine. He joins us from KUHF in Houston. Welcome back to SCIENCE FRIDAY.
DAVID EAGLEMAN: Thanks, Ira, nice to be here.
FLATOW: You're welcome. Sally, where - let me get back to you to talk a little bit more about your book. Where do you put the blame for the problem? Is it with scientists, university press offices, the media? Do you think they're misconstruing what they're saying about scanning?
SATEL: Oh to some extent, yeah, the mindlessness comes in in the oversimplification, and we do see that in the media. We do - it's important to draw a distinction between dedicated science journalists and I think general reporters. Science journalists tend to be far more sophisticated. They understand the process. They talk to scientists in general, and sometimes read the papers themselves, and they're very challenging academic papers to read.
But yes, the media can certainly oversimplify, and the interpretive license that's taken on occasion - and here I really say on occasion - by some neuroscientists has been striking. But they are very much the exception. And in fact one of the more striking examples of that, which occurred in - on the pages of the New York Times on an op-ed in about 2007 with brain imaging of swing voters, could we infer - you know, could you use brain imaging to infer what they thought of various candidates, and could this inform, then, campaigns to make the candidates more attractive, that particular op-ed was greeted, within 48 hours, by a letter signed by 17 neuroscientists objecting to the oversimplification.
So when that happens, their colleagues often tend to react. And then there's also another class that I call the neuro-entrepreneurs, which are businessmen who are promoting functional magnetic resonance imaging to serve as lie detection and also in some areas of neuro-marketing.
Neuro-marketing is a complicated field. Some of it's more serious than others. Other parts of it seem very, very hyped. But these are folks who are very much using science - using brain imaging in what I think are premature ways in the business context.
FLATOW: 1-800-989-8255 is our number. Gary Marcus, you published sort of a rebuttal in the New Yorker, I mean not really a rebuttal but a sort of pushback on this.
MARCUS: Yeah, the piece was more of a pushback again David Brook's(ph) interpretation, also in the New York Times, than Sally's book per se. So I think there's a lot to like about Sally's book. There's a terrific part about how you read a neuroimaging paper skeptically or a report in journalism. You know, what are the questions that you need to ask in order to tell whether a study is good?
If there's a weakness to the book, I think it's that it can be misinterpreted, and I think David Brooks was kind of the case in point. It can be taken as sort of throwing the baby out with the bathwater. I don't think the book actually does that. I think the emphasis on the subtitle is on mindless neuroscience.
If the book did one thing, or could have done one thing differently, I would have made the last chapter say a lot more about what mindful neuroscience might be, about what are the ways in which we can make neuroscience better. I was at an NIH panel yesterday, where people were talking about Obama's brain initiative. And there were about 20 speakers.
And everybody there was talking about new methods that I think are going to be more sophisticated. So one of the problems with neuroimaging is the basic unit is called a voxel, and it's about a millimeter cubed, and that has about 100,000 neurons in it. And so studying the brain by studying 100,000 neurons at the time is sort of like trying to understand politics by looking out of an airplane window. It's a very big abstraction.
And people are going to be able to do better. There's another way in which I mentioned in my piece, and which is mentioned in the book "Brainwashed," which is that there are now some techniques for looking at multiple areas doing their thing simultaneously. So a lot of early neuroimaging proceeded on the basis of assuming that there was a kind of one-to-one mapping: This piece of the brain does this particular task, so all emotion is in the amygdale.
And now we know better. It's a many-to-many mapping. So each different cognitive functions draws on many different pieces of the brain. But the consequence of that is not that we should throw up our hands, it's that we need better analytic techniques. And people in the last couple years have been developing those so that we can look at patterns of brain activation throughout the brain and sometimes do a good job of reconstructing what people are thinking.
So it's a very fluid field. Neuroimaging is just one of the techniques in neuroscience, and it's possible to do neuroscience in better ways, some now already, by looking at multiple brain areas simultaneously, and some by working at a higher level of resolution.
FLATOW: Dr. Poldrack, give us a little bit of a primer here. Let's talk about the type of scans that are commonly done. There is MRI, functional MRI. What are you actually measuring in these scans?
POLDRACK: Sure, so, you know, MRI is a very flexible method for looking inside the body. When you, say, go to the hospital because you had a headache, and the doctor wants to know what's going on, that's generally what we would refer to as a structural MRI. It's looking at the shape of things or sort of what the tissues are made out of.
Functional MRI doesn't look at that. It looks at actually what the brain is doing, its metabolism. So for example imagine - you know, picture in your head your childhood home. When you do that, parts of your brain that are involved in, say, representing visual images become more active. And when that happens, blood flow to those parts of the brain turns up.
And interestingly, it actually turns up more than it needs to, and you end up with a surplus with oxygen in those areas. So you have more oxygenated blood there than you usually would. It turns out that you can use MRI to actually see the difference between blood that has more oxygen versus less oxygen because the hemoglobin molecule that actually carries the oxygen acts differently in a magnetic field depending on whether it has an oxygen molecule in it.
And then what we can do is, say, for example, have you image your childhood home versus just relaxing and not imaging anything, and we can see - get a map of which parts of the brain are more active when you're doing that. But it's important to remember that we're not looking at neurons directly. We're looking at this indirect measure that uses blood oxygen levels.
FLATOW: And it's a long leap to go from seeing blood oxygen levels going up to understand what we're thinking when we see something like that.
POLDRACK: That is a long leap, though, you know, work has shown that we can actually decode what people are thinking, at least in very limited circumstances. We can decode with pretty much perfect accuracy if I show you some faces and some outdoor scenes, I can decode without almost - usually with perfect accuracy which of those you're looking at just by looking at the relative levels of activity across different parts of your brain.
As you get to higher-level thought, it gets a lot more complex and a lot more difficult.
FLATOW: David Eagleman, do you worry that someday that there are going to be these, you know, truth scans for courts because we can see what you're thinking?
EAGLEMAN: Well, sort of. There's been a lot of interest in the idea of having FMRI-based lie detection. As it stands now, it's probably not going to fly, and it's for a fundamental reason that we can't ever measure a lie in the brain. All we can ever measure is the physiologic responses associated with the lie.
So at least two companies started some years ago to see if they could do FMRI-based lie detection. At least one of them's out of business already because there are ways of doing counter-measures. And so this is not to say that it will never be better than the polygraph test, but at the moment it's not passing the standards for admissibility of evidence.
If I could just take one step back, though, to something, which is, you know, I think Sally in her book, and Scott there, sounding an appropriate note of caution. And as Gary said, you know, we can't - it's a crude technology in some ways. In some ways it's the fanciest technology we have, but in other ways we can't see more than the forest fires when we're looking down from that airplane.
But what is absolutely clear is that it makes good sense for us to be looking down from the airplane at the brain because we are irrevocably tied to this three pounds of this strange computational material that we find within our skulls, and that means our personalities, our hopes, our fears, our aspirations, the agony, the ecstasy. It's all tied in with this biological tissue.
And we know that because when the brain changes, you change, as well. So when people get strokes or tumors or traumatic brain injury or epilepsy or any kind of problems going on in their brain, their personality and decision-making change. And that's why it's not such a long leap to think that what's happening in the tissue maps onto what we're thinking and experiencing.
FLATOW: Thank you. We're going to take a short break and come back and talk lots more about brain imaging after this break. Stay with us.
(SOUNDBITE OF MUSIC)
FLATOW: I'm Ira Flatow. This is SCIENCE FRIDAY from NPR.
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FLATOW: This is SCIENCE FRIDAY. I'm Ira Flatow. We're talking this hour about brain scans and what they can and cannot tell us about human behavior, what people are thinking and all kinds of stuff about the - can they be used as truth tellers, sort of like in courtroom cases?
My guests are Sally Satel, co-author of "Brainwashed: The Seductive Appeal of Mindless Neuroscience," resident scholar at the American Enterprise Institute; Gary Marcus, professor of psychology at NYU; Russell Poldrack, a director of the Imaging Research Center at the University of Texas in Austin; David Eagleman, neuroscientist at Baylor College of Medicine. Our number is 1-800-989-8255.
Let's talk about - David, you were talking about using this in legal cases. Are there times where a person should be absolved of responsibility because of a brain abnormality?
EAGLEMAN: Well, this is the - this is the idea that Sally suggested in her book is a problem. She suggested that when neuroscientists study what happens with people's brains who commit crime, then the logical conclusion of that is that we will let them off the hook. That doesn't make sense. That's a misinterpretation of what people are trying to accomplish at the intersection of neuroscience and the law.
Instead, understanding what's happening with people's biology and how their biology or changes in that lead to their behavior leads us not to letting anybody off the hook, but instead it can lead to rational sentencing and customized rehabilitation. It leads to a more efficient and humane legal system by dropping the pretense that everybody's exactly the same on the inside because people are actually quite different on the inside.
If you're a judge, you can have three different people standing in front of your bench having committed exactly the same crime, but one of them is schizophrenic. One of them is a sociopath. One of them is tweaked out on drugs. You can have many more. And the point is that - the important question for the legal system to ask is what do we do moving forward.
Nobody gets off the hook; bad actors still get pulled off the street. But the question is can we have a tailored, customized system of sentencing and rehabilitation. That's the point of understanding neurobiology in the legal context.
FLATOW: 1-800-989-8255. Sally Satel, there's a chapter in your book that looks at addiction, and you say, let me paraphrase it, that there's a danger in making addiction appear as a brain disease. Can you elaborate on that?
SATEL: Oh yes, also, though, I'd like to just reflect on what David said a moment ago. As far as letting people off the hook, listen, that's why we have an insanity defense, and hopefully we will be much better at inferring people's rational capacity and ability to control themselves using imaging and using other kinds of brain-based techniques. And I certainly welcome that. Everyone wants to be informed by science as best they can.
I was actually referring to a fair amount of evidence that's simply empirical evidence that shows that when people hear behavior being described in biological and neurobiological terms, as opposed to psychological terms, that they are more likely to think the person is less responsible.
Now that doesn't mean that that's not an accurate conclusion to draw in some cases. My point is that brain scans at this time, their sophistication cannot help us make that distinction. Now that segues in nicely to addiction because, yes, I've been - I must say I've been a fairly vocal critic of this concept of addiction as a brain disease.
And the reason is because it's that phrase, that particular phrase brain disease, has been specifically analogized by the National Institutes of Health, which created this - that formulation - has been specifically analogized to conditions that we think of more traditionally as brain diseases, and by that I mean Alzheimer's disease, schizophrenia in its most florid form, Parkinson's.
And the problem with that analogy is again, I'm more interested in this brain disease idea as a public health message, which is the way it's often disseminated. And the problem with that formulation is that the other brain diseases are conditions in which, for example, you can't become better through your desire to be well.
You can't respond to foreseeable consequences when you have, for example, Alzheimer's. Now, I could say to a patient with Alzheimer's, if they understand me, if they could understand me, that I will reward you if your memory doesn't deteriorate, or I will punish you in some way, use some aversive stimulus, if it does. That wouldn't matter because the brain changes associated with Alzheimer's are the kind of that makes the person incapable of responding to that kind of logic and that sort of a proposition.
But thank goodness that's not true of people with addiction. And we use that to our advantage in my clinic and also in these entities called drug courts all the time where we set forth a behavioral program for people where if they complete certain tasks or fall short in others, there are consequences and rewards. And these are swift and certain, but they're not severe.
They're fair, so everyone in there - in the drug court, for example, gets the same treatment. And, as I said, they're predictable. And that's very, very important. These are elements of, you know, Behavior 101 when you're trying to shape behavior.
FLATOW: Let me ask Dr. Poldrack. Do you think it's useful to look for differences in the brains of addicts?
POLDRACK: So I guess I would start by saying I don't think anybody's arguing that, you know, addiction is only about what's going on in the brain. Clearly there are social factors and lots of other stuff going on at the same time. Knowing what's going on in the brain I think is going to be really useful in understanding how do you fix the problem.
So, you know, the book tries to sort of imply that any addict can cure themselves, and that the people who can't cure themselves are in the minority. If you look at the actual data, so look at the data on smokers, in 2010 according to CDC there were 45 million or so people who were smoking. More than half of them tried to quit that year. Only 6.2 percent were successful.
And in fact if you look at the contingency management programs of the type that she talks about in the book, you see that they're more effective than other treatment, but they're still only effective for maybe a little more than half of people. So I think first, you know, that suggestion is debatable.
The other thing we know from neuroscience is that, you know, basically every drug that people get addicted to targets the same system in the brain, the dopamine system. And this is the system that we know is involved in basically strengthening some behaviors and weakening other behaviors. That seems like something that's worth knowing, and it could be useful in understanding why it is that so many people have a hard time actually quitting tobacco or alcohol or other drugs.
FLATOW: Gary, do you have any reaction to that?
MARCUS: I'd say that the potential for neuroscience here, echoing Russell a little bit, is in looking at people that have the same symptoms but different underlying disorders. So just like you can have a headache because you have a brain tumor, or just because you have a migraine or tension and so forth, if you have extra tools that you can go beyond the symptom to understand different underlying disorders, that's a great thing.
And I think that brain science has the potential to do that. I'm not sure we're entirely there yet. But you can think that addiction, for example, for some people it's about the potency of the reward. For some people it's about self-control. Different people are going to be addicted for different reasons, and in the long run we hope that we'll be able to get some insight and therefore be able to pick different treatment programs for different people.
FLATOW: Dr. Eagleman?
EAGLEMAN: Yeah, the way to understand the brain is to understand that you're not just a single decision-maker, but instead you have a competition of different sub-populations in the brain that want different things. So for cocaine addicts, which we're working with in my lab now, you know, most of them want to quit, but they've found themselves unable, the ones that we're working with.
And so there are parts of them that can really crave the cocaine, and they will give in to that temptation most of the time, but there are other parts of their brain that can list all of the reasons - the financial cost, the cost of their family and so on - and they want to quit.
And what's happening under the hood is essentially a battle between different political parties. And so to echo what Russell said about why neuroscience is really useful here is because we can use that sort of knowledge that we gain from neuroimaging, let's say, to come up with tools to try to help them.
So one of the things we're doing in my lab is real-time feedback in FMRI, where we are essentially giving them visual feedback about what's happening under the hood. So we take an addict who wants to quit, put them in the scanner, show them pictures of cocaine, and we ask them to crave, and we measure those networks in their brain that are specifically involved in that craving, and we represent the activity in those networks by a speedometer on the screen.
And their job is to make that speedometer go down, and they're doing that by reducing the activity in those networks. And as they figure out how to do that, they're better and better able to make that speedometer go down. It's the prefrontal gym is what I call it because they're strengthening that up.
FLATOW: I see Sally wants to jump in here.
FLATOW: Yes, go ahead.
SATEL: Yes. I do want to make sure you realize this is not an either/or proposition here. I certainly agree that we'll learn more about the neural underpinnings of motivation, reward, and memory, and self-control and impulse control, which are key in addiction, and that I - in no way are Scott and I somehow against biological exploration of this complex behavior.
What we are - what actually we're cautioning against and we've recognized - in fact, we speak about the biology of addiction in the article - I mean, excuse me, in our chapter. But what we want to make sure is that the attention isn't pulled almost exclusively towards that end and it also remains very much in the psychological realm, understanding that people use drugs for reasons, and also in the environmental and social.
And if I can just add something. I know we have lots of topics to cover, but chronic and relapsing disease is actually from - which is really the full formulation of the brain disease. It's supposedly a chronic and relapsing brain disease. Epidemiologically, what we see is that the subset of people who are the chronic and relapsing folks are the ones with the comorbid mental illnesses, which is very important to know about for smokers.
In fact, 95 percent ultimately quit. And it's very interesting to think about smoking itself because, as a behavior, you know, when we think about actions and the kinds of - again, the consequences that shape it, smoking compared to - which is addicting. There's no question nicotine and smoking are addicting. But the immediate consequences for that are so much less...
FLATOW: Mm-hmm. All right.
SATEL: ...because it's non-intoxicating and so on. Legal - yes. OK.
FLATOW: I want to - I do want to move on a little because we're running out of time. I want - Gary, is part of the problem people have with much of this brain research that it reduces us, in some way, to just our biology, that we have no free will, it's all wired in there?
MARCUS: Well, there's a kind of funny tension because, on the one hand, brain science is kind of the prestige science, so people want to worship it. But at the same time, they're kind of afraid of the brain science because they think it leads to a lack of free will.
I'm not sure I can actually answer the free will question. But I would say that there's a really good point that Sally is making that should be brought out more clearly, which is that neuroscience does get privileged, in a way, and so people treat it as if it's the final explanation. And maybe 100 years from now, it will be, but right now, we really do need neuroscience and psychology working together.
So psychology uses terms like we just heard, like motivation, reward and so forth, and neuroscience tends to talk about particular areas and particular circuits. And our real job should be to bridge those two, not to talk just in one, not to say, hey, the neuroscience language is the important one here, but to say, how do we work between these two?
And if we ever figure out an answer to free will, it's also going to come from understanding the relation between psychological terminology like desires, beliefs and so forth and the underlying neuromechanism.
FLATOW: Dr. Poldrack, in a few minutes we have left, how can, following up on Gary's point, how can the public, the lay public, learn to be more critical of the kinds of types of studies and to know which, you know, are better than the others?
POLDRACK: I mean, you know, I would echo the earlier comments. I think that Sally's book actually does a nice job of laying out, you know, some of the ways to think about that. So I think, you know, one thing to think about is if some - if you see, you know, an article that says, we found the part of the brain that does X, where X is, you know, love or whatever X might be, that's - you probably want to be a little bit skeptical of that because it's become pretty clear that there - you know, as Gary said earlier, there isn't a - there's very rarely a one-to-one mapping between brain parts and psychological functions.
FLATOW: Mm-hmm. This is SCIENCE FRIDAY from NPR. I'm Ira Flatow, talking about brain scans. And you mentioned it before as we're wrapping up, Gary. What are the new scans? You said you had a meeting of new scans? What kind of things can they do?
MARCUS: The goal is to measure every neuron simultaneously. I don't know if that's going to happen anytime soon in the human being. People are trying to do that, first, in, say, in flies and worms and mice and so forth, but that's one of the goals.
One of the most exciting studies that I've seen recently measured a goldfish, looked at the entire brain of the goldfish, every neuron more or less simultaneously. It's too slow to answer a lot of questions because it only gets about, I think, a frame a second or something like that, and a lot of things that happen in the brain happen 100 times a second.
So we don't have any sort of one-size-fits-all methodology, and there's a great paper that just came out about this online. We need to work together to put a lot of methodologies together in order to really get a complete portrait of the brain.
FLATOW: Mm-hmm. And are we worried at all - let's talk about legal stuff - that brain scan techniques and conclusions will be entering in courtrooms anytime soon?
EAGLEMAN: Yeah. This is David. Sure, they will be, but happily, we already have standards for the admissibility of evidence in courtrooms - so these are the Frye and Daubert standards - and also other federal rules of evidence that allow certain kinds of evidence to get excluded.
So I'm actually not worried that fMRI will get into courts inappropriately because, just like any other technology, they have to pass certain bars to be allowed as evidence into a case. So, you know, general acceptability in the field. Can you extrapolate from group studies to this individual in front of the bench? Do we know that this works outside of the laboratory in real-world situations?
And until fMRI passes those, it's not, I think, a concern that it'll be taking over the legal system. The other very important point about that is this idea that if something is wrong with somebody's brain, I think Sally's concern is that that might lead to the sense of mitigation where the person gets off the hook.
But I get - I just want to say, I get calls from defense attorneys once every few weeks where they'll say, hey, I've got a client. He's up for murder. Can you scan his brain and see if there's something wrong with it so we can get him off? And I always tell them, look, I'll give you a piece of free advice, which is if you find something really wrong with your client's brain, the jury is going to say, great, let's fry the guy for sure then, because it's not mitigating in any way.
Instead, all it does is it tells the jury that they can reasonably expect that kind of behavior into the future. So there's no reason why showing a fundamental problem of somebody's brain would be mitigating.
FLATOW: Mm hmm. We've ran out of time. I want to thank all of you for taking time to be with us today, Sally Satel, co-author of "Brainwashed: The Seductive Appeal of Mindless Neuroscience." She's resident scholar at the American Enterprise Institute. Gary Marcus, professor of psychology at NYU and - the article's name in The New Yorker?
MARCUS: It was something about the backlash against neuroscience.
FLATOW: Exactly. And Russell Poldrack is director of the Imaging Research Center at University of Texas at Austin, David Eagleman, neuroscientist at the Baylor College of Medicine. Thank you all for taking time to be with us today.
MARCUS: Thank you.
SATEL: Thank you.
EAGLEMAN: You're welcome.
FLATOW: We're going to take a short break. And when we come back, we're going to change gears and talk about astronomy, finding the first three planets, three for one, a trifecta of planets in the Goldilocks zone around a star. Quite an interesting development in astronomy. So stay with us. We'll be right back after this break. I'm Ira Flatow. This is SCIENCE FRIDAY from NPR. Transcript provided by NPR, Copyright NPR.